GN Audio Standardize Production Test to Ensure Quality

Csaba Fodor – Senior Test Engineer & Platform Lead—GN Audio

Christian Wolf – Manager, Global Manufacturing Test – GN Audio 

 

Case Study Highlights

  • Challenge—Meet test coverage, development schedule, and company-wide data-sharing requirements for increasingly complex, high-volume DUTs.  

  • Solution—Successfully deployed a standardized test platform for more than 20 products, across six manufacturing sites globally, based on NI measurement hardware, TestStand, and CATS software from CIM.AS

  • Success—Reduced test development from months to weeks despite a 2.5X test coverage increase on new products. Made test data accessible across company and suppliers.

  • Value—Reduced development times, Reduced data analysis times, and Quickly identified test failure rate changes

     

The Challenge

GN Audio required a new production test platform for their Jabra consumer electronics product lines. It needed to scale to higher test coverage requirements which shortening development effort.

The Solution

Their solution use COTS hardware and Software from NI and CIM.AS. It met their expanded test coverage needs and reduced development from months to weeks. This system is now successfully deployed across six manufacturing sites globally.

GN Audio is a leader in engineering communications and sound solutions, innovating to empower both consumers and businesses. Proudly part of the GN Group, we are committed to helping people hear more, do more, and be more than they ever thought possible. Through sound and video, we transform lives. Jabra engineering excellence leads the way, building on 150 years of pioneering work—using it, we create integrated headsets and communications tools that help professionals work more productively; wireless headphones and earbuds that let consumers better enjoy calls, music, and media; and pioneering video conferencing solutions for seamless collaboration between distributed teams.
 

The GN Group, founded in 1869, operates in 100 countries and delivers innovation, reliability, and ease of use. Today, GN employs 6200 people, and is Nasdaq Copenhagen listed. GN makes life sound better.

 

 

 

Consumer expectations have evolved over recent years to demand “premium” electronics that can be status symbols as well as functional devices. To be competitive, devices must meet significantly higher quality standards, have more functionality, and be available at an accessible price point. For example, when GN Audio created a new market category with the launch of our miniaturized wireless earbuds, we still had to match the audio quality expectation set by other larger products in our line. Whereas high-definition music, reliable wireless, and extended battery life were once product differentiators, now, they’re table-stakes.

Leveraging GN's vast experience in top-end hearing aid design, our R&D engineers excelled at addressing these product challenges—assembling multiple microphones, accelerometers, processors, radios, and more into a very small package.


The pressure is on test engineering to ensure every product we ship works correctly: As audio device quality increases, so do acoustic test station complexity and precision. With complete test-time specification in the tens of seconds, steps include:
 

  • Device communication test

  • Near-field magnetic induction test

  • Bluetooth pairing

  • Battery test 

  • Multiple acoustic transmitter tests 

  • Multiple acoustic receiver tests 

  • Multiple microphone calibrations

  • Multiple receiver calibrations 

  • User interface (UI) test (buttons and LEDs)

 

We used the GN acoustic test platform to test more than 80 different products and variants. To meet their varying requirements required more sophisticated sequencing and automation. The production test team faced increasing test complexity, higher measurement precision/repeatability expectations, more automation, and a need to making data-sharing easier.

 

Pressure on GN Production test Organization
 

  • Complexity—Test-coverage requirements increased by 2.5X in a recent new product introductions
  • Quality—Increased precision and repeatability of test measurement specifications.
  • Life Cycle—GN test development team supports six global manufacturing sites operated by EMS partners
  • Development Schedule—The business-need to be first to market squeezed test development schedule from months to weeks
  • Manufacturing Volume— Demand for consumer electronics such as earbuds and office headsets significantly increased by work and lifestyle changes
  • Data—Growing demand for test data by wider set of functions within GN Audio and suppliers

 

Our previous test solution was an in-house-developed platform that we had added to and evolved over 10+ years. It was obvious that this strategy was becoming a liability to the company as new functionality (measurement types and Windows OS integration) was difficult to implement, bug-fixing was very time-consuming, and staff onboarding was lengthy and inefficient. 

 

Use of commercial-off-the-shelf (COTS) tools

We moved to a strategy that uses commercial-off-the-shelf (COTS) hardware and software when possible for standard tasks such as process design, analysis, and reporting. Partnering with test experts and leveraging their tools for these tasks meant that our team could focus on writing and executing DUT-specific tests, which is where our team adds the most value. And as DUT complexity increases, it is critical to find higher-level starting points upon which we can build our test stations if we are to meet business demands. 

 

This strategy shortened development time, improved test quality/repeatability and reduced the maintenance burden, while providing flexibility for the future. It also lowered the level of domain expertise required for an engineer on the team to be effective, resulting in easier hiring and employees working across a wider set of projects.

 

 

Hardware

Acoustic tests are made over the air within an anechoic chamber. Each test fixture’s configuration is unique to the DUT; however, we use a common set of components whenever possible allowing for ease of sustaining at manufacturing sites across the world. GRAS speakers and microphones, configured into artificial mouths and ears, provide accuracy and reliability within manufacturing. These are connected through a microphone power supply to an NI DAQ board integrated within the test system. 

 

We consider NI DAQ hardware the industry standard for production test applications. The close integration with NI software ensures ready access to our coverage requirements. NI tools are well-known throughout the industry, which means that new hires and consultants can ramp up quickly which shortens schedules and improves development quality.

 

We develop and maintain the test station mechanical infrastructures and fixtures in-house because our team possesses the necessary skillsets. Thus, we achieve full customization while minimizing the financial investment requirement per station.

 

Software

Reuse is key to our software strategy. Many of the required tests are common, needing only frequency range variation, but increasingly, new DUTs require entirely new measurements too. To ensure efficient ongoing development and stable operation, we developed a scalable software architecture leveraging COTS tools with which we could add and reuse measurements. 

 

We used these software tools:

 

  • TestStand—We chose this industry-standard sequencer for its process model and plugin architecture that make customization easier and quicker. NI TestStand opens new possibilities, with built-in parallel testing and reporting functionality.

 

  • CATS from CIM.AS—We chose this audio test solution software because it shortens development time, ensures analysis algorithm quality, and introduces new capabilities that improve test coverage. We used CATS for signal generation, analysis, results logging, and measurement-system calibration.

 

  • LabVIEW—This test engineering development environment offers data acquisition, data communication, and GUI design. We chose it for its rapid development, close hardware integration, and interoperability with a wide ecosystem of other software tools. 

 

 

With the correct mix of software tools abstracting common tasks and architectures, our test team could focus on designing high-accuracy, highly repeatable tests using our specific knowledge of the DUT operation.

 

Production volume is expected to increase in coming years, which will require higher levels of automation. As this automation is implemented, the abstraction or outsourcing of standard processes will become more critical. We expect the engineering team to face increasing challenges while conscientiously managing budgets and headcount. 

 

Data

There is a growing demand from across the company for production test station data insight. Beyond the usual functions of test operations and development, in-market engineers, design verification, audio engineering, and hardware design engineers also request test data as an input to their work. Our production testers create more than 5 GB of test data each day, which results in TB of data across the company—and without proper management, it is easy for data to be mislabeled, misused, or misunderstood. 

 

Each function uses this data differently, requiring multiple dashboards and searchability options. To meet these requests, test engineering has adopted common data formats, storage, and communication. Functions across the company now can generate their own reports from test data, rather than requesting them from test engineering. This has saved many hours of time for our team. Through effective data availability, test engineering can deliver value throughout the company, contributing to the quality of both existing and new product designs.

 

Partnership

One key element to this project’s success was the collaboration between a community of engineers across several companies. It is frustrating and inefficient to spend time reinventing the wheel—but it’s equally frustrating when a partner delivers a wheel when you are trying to design a lever. 

 

In our partnership with CIM.AS, we found a group of engineers who specialize in production and acoustical testing and were willing spend the time to understand our business, our application, and our test coverage. Together with NI, they provided tools and consultation that kept us at the cutting edge of technology and supported our goals. 

 

CIM.AS has decades of experience designing and building acoustic and electrical test stations. Their trusted engineering support gives us confidence that we can deliver our high-quality test stations on schedule to our manufacturing sites across the world. 

 

Results compared to previous solution testing similar DUTs
 

  • Complexity—Met test coverage using existing resources despite 2.5X complexity increase
  • Quality—Maintained measurement repeatability and accuracy, cementing consumer confidence in GN Audio acoustic and electrical product performance
  • Life Cycle—Deployed successfully at six global manufacturing sites with minimal sustaining and maintenance requests returning to test development team
  • Development Schedule—Development of functional test for NPI reduced to two weeks using standardized platform architecture and rapid development tools such as NI TestStand and CATS from CIM.AS.
  • Manufacturing Volume—Met manufacturing volume requirements, ranging from tens of thousands to millions depending on the product line
  • Data—Gave R&D, validation, test, and operations functions access to production data from prototype to production, contributing to new product design quality

 

Figure 1. Earbud product features requiring test coverage.
Figure 2. Architecture of test station